Contboii device fob iqnitioit timers



-May 24, 1932. M. MALLORY CONTROL DEVICE FOR IGNITION TIMERS Filed Oct.12, 1931 gwoentoc Patented May 24, 1932 nBION MALLORY, OF TOLEDO, OHIO(DNTBOL DEVICE FOR IGNITION TIMEBS Application filed October 12, 1931.Serial No. 568,287.

This invention relates to a control device for ignition timers, withparticular reference to the condition present when, with the engineidling, the t rottle is suddenly o ened.

In order to insure a smooth and stea y operation when the engine isidling, it is necessary to set the timer so that the spark will occurwhen the crank is 5 to 10 past dead center. With such setting, when thethrottle is open, if the initial spark advance depends primarily upon acentrifugal governor, no advance will take place until there has been aconsiderable increase in'speed and as a consequence the fpick-up will beslow. On the other hand, i the spark is initially set where it should befor the best performance after the throttle is opened, it Wlll cause theoperation of the engine to be jerky when idling or perha s to stopaltogether.

Wit the above facts in mind, it is the object of the present inventionto control the timing automatically in such a manner that in idling thespark will occur when the crank is at an appreciable angle past deadcenter, but when the throttle is opened, the spark will be immediatelyadvanced so that it will occur before the crank reaches dead center. Thesubsequent control of the timing as the speed of the engine increasesmay be effected by any suitable means. That is, it may be controlledsolely by a centrifugal governor, by the vacuum in the fuel intake, orby a combination of both, or it may be controlled manually b aconnection withthe throttle or indepen ently thereof.

The present embodiment of m invention will be more articularly descri edin connection with the accompanying drawings, in which- Figure 1 is avertical sectional view of a timer with which the invention isassociated;

V Figure 2 is a section taken on the line 2-2 of Figure 1;

Figure 3 is a section takenon the line 33 of Figure 1;

. Fi of Figure 1; and

Fi re 5 is a section of the timer similar to Figure 4, but shows inconnection therewith a modified form of the invention.

re 4 is a section taken on the line As shown in the drawings, theinvention is associated with an ignition timer comprising a housing 10formed with a bearing 11 for the timer shaft 12. A sleeve 13 is mountedfor relative circumferential movement on the shaft 12 and is providedwith a cam 14: which actuates the circuit breaker 15. The relativeposition of the sleeve 13 and cam 14 with reference to the timer shaft12 is controlled through the medium of a circular plate 16 which issecured to the sleeve other suitable means.

The position of the plate 16, as the speed of operation increases, isusually controlled by screws 17 or by a suitable centrifugal governorwhich, in u 21 which 70 which is eccentric to the axis of the weight 75so as to cause an advance movement of the plate 16 and circuit breaker14 as the weight is moved outwardly under the influence of centrifu a1force.

In or ance with the invention, when the engine is idling, the housing 10is formed with a lateral extension 24 within which a piston 25 isoperable. The piston has a stem 26 which er to control the timing inaccord- 80 is adapted to project into a bore'27 extending through thewall of the housing in the same plane as the plate 16. The inner end ofthe stem 26, when it comes in contact with the edge of the plate 16,acts as a brake on the latter to retard the spark. The extension 24houses a coil spring 28 which normally acts against the head of thepiston to urge the latter toward the outer end of the housing, thusmoving the brake out of contact with the plate 16.

The cavity which contains the spring 28 has a port 29 connected by asuitable conduit 30 with the intake manifold or some other part of thefuel intake as indicated at 31.

Thus, when the throttle is closed, so that the operation of the engineeven though idling causes a considerable vacuum in the fuel intakepassageway 31, the suction thus created overcomes the tension of thespring 28 and causes the inner end of the stem 26 to act on the plate 16to retard the spark so that it will take place after the crank haspassed dead center. This insures a steady operation when idling. Whenthe throttle is opened, this immediately relieves the vacuum in thepassageway 31 sufliciently to permit the spring 28 to act on the head ofthe piston 25 and relieve the plate 16 from the action of the brake. Theresult is that whenever the throttle is opened the spark is immediatelyadvanced so that it occurs at 5 or 10 in advance of dead center and itssubsequent timing will, in the present instance, be controlled by thenormal action of the centrifugal governor. When the engine is operatingat high speed, there may be suflicient vacuum in the intake to againapply the brake but by that time the centrifugal force on the governorwill be suflicient to overcome the friction of the brake and hold thespark advanced.

In the modification shown in Figure 5, the same retardation of thespark, when the engine is idling, is eflected directly through theoperation of the throttle rod 32 by which the throttle valve 33 iscontrolled through .the medium of the arm 34. In this construction thethrottle rod 32 is connected by any suitable means with a rocker arm 35mounted on a bracket 36 located adjacent the extension 24. The end 37 ofthe rocker arm 35 is adapted to engage the end 38 of the piston 25,which projects beyond the end of the extension 24. As shown, there is alost motion between the throttle rod 32 and the rocker arm 35. As thethrottle rod 32 is advanced to close the throttle valve 33 for idling,it rocks the arm 35, causing the end 37 to engage the projecting end ofthe piston and to move the brake into frictional contact with theplate'lfi, thus retarding the spark. As soon as the throttle rod 32 ismoved in the opposite direction to open the throttle valve 33 eitherpartially or fully, the piston 25 is immediately under control of thespring 28 and the brake is withdrawn from contact with the plate 16.

From the foregoing description, it will be seen that I have provided atimer controlling device which may be initially set so that in idlingthe spark will occur after the crank passes dead center and yet, themoment the throttle is opened, the brake is moved to inoperativeposition, permitting the spark to advance immediately to a normalposition 5 or 10 in advance of dead center, after which it may becontrolled in any suitable manner in accordance with the speed of theengine or other conditions under which the engine is operated.

It will be understood that the invention may be further modified invarious respects without departing from the scope of the invention asdefined in the claims.

What is claimed is:

1. In an internal combustion engine, the combination with a timer shaftand a circuit breaker cam movable circumferentially with respectthereto,'said cam being initially set for causing a spark after passingdead center position when the engine is idling, of means for immediatelyadvancing the cam, when the throttle is opened, to-cause the spark tooccur in advance of dead center position.

2. In an internal combustion engine, the combination with a timer shaftand a circuit breaker cam movable circumferentially with respectthereto, of means acting on said cam to delay the spark only when theengine is idling.

3. 11 an internal combustion engine, the combination with a timer shaftand a circuit breaker cam movable circumferentially with respectthereto, of means rendering the timing later than normal only when theengine is idling.

4. In an internal combustion engine, the combination with a timer shaftand a circuit breaker cam movable circumferentially with respectthereto, of means for normally controlling the timing in accordance withthe speed of the engine, and means rendering the timing later thannormal only when the engine is idling.

5. In an internal combustion engine,- the combination with a timer shaftand a member including a circuit breaker cam movable circumferentiallywith respect to the shaft, of a brake, and means for applying the braketo said member only when the engine is idling.

6. In, an internal combustion engine, the combination with a timer shaftand a member including a circuit breaker cam movable circumferentiallywith respect to the shaft, of

8. In aninternal combustion engine, the 1 combination with a timer shaftand a member including a c'rcuit breaker cam movable circumferentiall ywith-res ect to the shaft, of a brake operable by suction from the fuelintake passage of the engine to engage said

